skip leading zeros even after decimal point in floatscan

in principle this should just be an optimization, but it happens to
also fix a nasty bug where values like 0.00000000001 were getting
caught by the early zero detection path and wrongly scanned as zero.

diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c
index b260381..dbe0798 100644 (file)
--- a/src/internal/floatscan.c
+++ b/src/internal/floatscan.c
@@ -57,10 +57,10 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
        uint32_t x[KMAX];
        static const uint32_t th[] = { LD_B1B_MAX };
        int i, j, k, a, z;
        uint32_t x[KMAX];
        static const uint32_t th[] = { LD_B1B_MAX };
        int i, j, k, a, z;

-       long long lrp=-1, dc=0;
+       long long lrp=0, dc=0;

        long long e10=0;
        int lnz = 0;
        long long e10=0;
        int lnz = 0;

-       int gotdig = 0;
+       int gotdig = 0, gotrad = 0;

        int rp;
        int e2;
        long double y;
        int rp;
        int e2;
        long double y;


@@ -74,11 +74,16 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
 
        /* Don't let leading zeros consume buffer space */
        for (; c=='0'; c = shgetc(f)) gotdig=1;
 
        /* Don't let leading zeros consume buffer space */
        for (; c=='0'; c = shgetc(f)) gotdig=1;

+       if (c=='.') {
+               gotrad = 1;
+               for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
+       }

 
        x[0] = 0;
        for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
                if (c == '.') {
 
        x[0] = 0;
        for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
                if (c == '.') {

-                       if (lrp!=-1) break;
+                       if (gotrad) break;
+                       gotrad = 1;

                        lrp = dc;
                } else if (k < KMAX-2) {
                        dc++;
                        lrp = dc;
                } else if (k < KMAX-2) {
                        dc++;


@@ -95,7 +100,7 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
                        if (c!='0') x[KMAX-3] |= 1;
                }
        }
                        if (c!='0') x[KMAX-3] |= 1;
                }
        }

-       if (lrp==-1) lrp=dc;
+       if (!gotrad) lrp=dc;

 
        if (gotdig && (c|32)=='e') {
                e10 = scanexp(f, pok);
 
        if (gotdig && (c|32)=='e') {
                e10 = scanexp(f, pok);